1 // Copyright David Abrahams 2002.
2 // Distributed under the Boost Software License, Version 1.0. (See
3 // accompanying file LICENSE_1_0.txt or copy at
4 // http://www.boost.org/LICENSE_1_0.txt)
5 #ifndef EXTRACT_DWA200265_HPP
6 # define EXTRACT_DWA200265_HPP
7
8 # include <boost/python/detail/prefix.hpp>
9
10 # include <boost/python/converter/object_manager.hpp>
11 # include <boost/python/converter/from_python.hpp>
12 # include <boost/python/converter/rvalue_from_python_data.hpp>
13 # include <boost/python/converter/registered.hpp>
14 # include <boost/python/converter/registered_pointee.hpp>
15
16 # include <boost/python/object_core.hpp>
17 # include <boost/python/refcount.hpp>
18
19 # include <boost/python/detail/copy_ctor_mutates_rhs.hpp>
20 # include <boost/python/detail/void_ptr.hpp>
21 # include <boost/python/detail/void_return.hpp>
22 # include <boost/call_traits.hpp>
23
24 #if BOOST_WORKAROUND(BOOST_INTEL_WIN, <= 900)
25 # define BOOST_EXTRACT_WORKAROUND ()
26 #else
27 # define BOOST_EXTRACT_WORKAROUND
28 #endif
29
30 namespace boost { namespace python {
31
32 namespace api
33 {
34 class object;
35 }
36
37 namespace converter
38 {
39 template <class Ptr>
40 struct extract_pointer
41 {
42 typedef Ptr result_type;
43 extract_pointer(PyObject*);
44
45 bool check() const;
46 Ptr operator()() const;
47
48 private:
49 PyObject* m_source;
50 void* m_result;
51 };
52
53 template <class Ref>
54 struct extract_reference
55 {
56 typedef Ref result_type;
57 extract_reference(PyObject*);
58
59 bool check() const;
60 Ref operator()() const;
61
62 private:
63 PyObject* m_source;
64 void* m_result;
65 };
66
67 template <class T>
68 struct extract_rvalue : private noncopyable
69 {
70 typedef typename mpl::if_<
71 python::detail::copy_ctor_mutates_rhs<T>
72 , T&
73 , typename call_traits<T>::param_type
74 >::type result_type;
75
76 extract_rvalue(PyObject*);
77
78 bool check() const;
79 result_type operator()() const;
80 private:
81 PyObject* m_source;
82 mutable rvalue_from_python_data<T> m_data;
83 };
84
85 template <class T>
86 struct extract_object_manager
87 {
88 typedef T result_type;
89 extract_object_manager(PyObject*);
90
91 bool check() const;
92 result_type operator()() const;
93 private:
94 PyObject* m_source;
95 };
96
97 template <class T>
98 struct select_extract
99 {
100 BOOST_STATIC_CONSTANT(
101 bool, obj_mgr = is_object_manager<T>::value);
102
103 BOOST_STATIC_CONSTANT(
104 bool, ptr = is_pointer<T>::value);
105
106 BOOST_STATIC_CONSTANT(
107 bool, ref = is_reference<T>::value);
108
109 typedef typename mpl::if_c<
110 obj_mgr
111 , extract_object_manager<T>
112 , typename mpl::if_c<
113 ptr
114 , extract_pointer<T>
115 , typename mpl::if_c<
116 ref
117 , extract_reference<T>
118 , extract_rvalue<T>
119 >::type
120 >::type
121 >::type type;
122 };
123 }
124
125 template <class T>
126 struct extract
127 : converter::select_extract<T>::type
128 {
129 private:
130 typedef typename converter::select_extract<T>::type base;
131 public:
132 typedef typename base::result_type result_type;
133
operator result_typeboost::python::extract134 operator result_type() const
135 {
136 return (*this)();
137 }
138
139 extract(PyObject*);
140 extract(api::object const&);
141 };
142
143 //
144 // Implementations
145 //
146 template <class T>
extract(PyObject * o)147 inline extract<T>::extract(PyObject* o)
148 : base(o)
149 {
150 }
151
152 template <class T>
extract(api::object const & o)153 inline extract<T>::extract(api::object const& o)
154 : base(o.ptr())
155 {
156 }
157
158 namespace converter
159 {
160 template <class T>
extract_rvalue(PyObject * x)161 inline extract_rvalue<T>::extract_rvalue(PyObject* x)
162 : m_source(x)
163 , m_data(
164 (rvalue_from_python_stage1)(x, registered<T>::converters)
165 )
166 {
167 }
168
169 template <class T>
170 inline bool
check() const171 extract_rvalue<T>::check() const
172 {
173 return m_data.stage1.convertible;
174 }
175
176 template <class T>
177 inline typename extract_rvalue<T>::result_type
operator ()() const178 extract_rvalue<T>::operator()() const
179 {
180 return *(T*)(
181 // Only do the stage2 conversion once
182 m_data.stage1.convertible == m_data.storage.bytes
183 ? m_data.storage.bytes
184 : (rvalue_from_python_stage2)(m_source, m_data.stage1, registered<T>::converters)
185 );
186 }
187
188 template <class Ref>
extract_reference(PyObject * obj)189 inline extract_reference<Ref>::extract_reference(PyObject* obj)
190 : m_source(obj)
191 , m_result(
192 (get_lvalue_from_python)(obj, registered<Ref>::converters)
193 )
194 {
195 }
196
197 template <class Ref>
check() const198 inline bool extract_reference<Ref>::check() const
199 {
200 return m_result != 0;
201 }
202
203 template <class Ref>
operator ()() const204 inline Ref extract_reference<Ref>::operator()() const
205 {
206 if (m_result == 0)
207 (throw_no_reference_from_python)(m_source, registered<Ref>::converters);
208
209 return python::detail::void_ptr_to_reference(m_result, (Ref(*)())0);
210 }
211
212 template <class Ptr>
extract_pointer(PyObject * obj)213 inline extract_pointer<Ptr>::extract_pointer(PyObject* obj)
214 : m_source(obj)
215 , m_result(
216 obj == Py_None ? 0 : (get_lvalue_from_python)(obj, registered_pointee<Ptr>::converters)
217 )
218 {
219 }
220
221 template <class Ptr>
check() const222 inline bool extract_pointer<Ptr>::check() const
223 {
224 return m_source == Py_None || m_result != 0;
225 }
226
227 template <class Ptr>
operator ()() const228 inline Ptr extract_pointer<Ptr>::operator()() const
229 {
230 if (m_result == 0 && m_source != Py_None)
231 (throw_no_pointer_from_python)(m_source, registered_pointee<Ptr>::converters);
232
233 return Ptr(m_result);
234 }
235
236 template <class T>
extract_object_manager(PyObject * obj)237 inline extract_object_manager<T>::extract_object_manager(PyObject* obj)
238 : m_source(obj)
239 {
240 }
241
242 template <class T>
check() const243 inline bool extract_object_manager<T>::check() const
244 {
245 return object_manager_traits<T>::check(m_source);
246 }
247
248 template <class T>
operator ()() const249 inline T extract_object_manager<T>::operator()() const
250 {
251 return T(
252 object_manager_traits<T>::adopt(python::incref(m_source))
253 );
254 }
255 }
256
257 }} // namespace boost::python::converter
258
259 #endif // EXTRACT_DWA200265_HPP
260